Improvement in Blood Supply After "Heparin-Dextran" Therapy in Patients of Buerger's Disease with Critical Limb Ischemia

Guidelines for management of actual or suspected inadvertent intra-arterial injection of sclerosants

BACKGROUND

Inadvertent intra-arterial injection of sclerosants is an uncommon adverse event of both ultrasound-guided and direct vision sclerotherapy. This complication can result in significant tissue or limb loss and significant long-term morbidity.

OBJECTIVES

To provide recommendations for diagnosis and immediate management of an unintentional intra-arterial injection of sclerosing agents.

METHODS

An international and multidisciplinary expert panel representing the endorsing societies and relevant specialities reviewed the published biomedical, scientific and legal literature and developed the consensus-based recommendations.

RESULTS

Actual and suspected cases of an intra-arterial sclerosant injection should be immediately transferred to a facility with a vascular/interventional unit. Digital Subtraction Angiography (DSA) is the key investigation to confirm the diagnosis and help select the appropriate intra-arterial therapy for tissue ischaemia. Emergency endovascular intervention will be required to manage the risk of major limb ischaemia. This includes intra-arterial administration of vasodilators to reduce vasospasm, and anticoagulants and thrombolytic agents to mitigate thrombosis. Mechanical thrombectomy, other endovascular interventions and even open surgery may be required. Lumbar sympathetic block may be considered but has a high risk of bleeding. Systemic anti-inflammatory agents, anticoagulants, and platelet inhibitors and modifiers would complement the intra-arterial endovascular procedures. For risk of minor ischaemia, systemic oral anti-inflammatory agents, anticoagulants, vasodilators and antiplatelet treatments are recommended.

CONCLUSION

Inadvertent intra-arterial injection is an adverse event of both ultrasound-guided and direct vision sclerotherapy. Medical practitioners performing sclerotherapy must ensure completion of a course of formal training (specialty or subspecialty training, or equivalent recognition) in the management of venous and lymphatic disorders (phlebology), and be personally proficient in the use of duplex ultrasound in vascular (both arterial and venous) applications, to diagnose and provide image guidance to venous procedure. Expertise in diagnosis and immediate management of an intra-arterial injection is essential for all practitioners performing sclerotherapy.

Comparative Analysis of Transcriptome Profiles in Patients with Thromboangiitis Obliterans

BACKGROUND

Thromboangiitis obliterans (TAO) causes vascular insufficiency due to chronic inflammation and abrupt thrombosis of the medium and small arteries of the extremities. In our study, we aimed to determine biomarkers for the diagnosis of TAO by evaluating 15 male TAO patients with Shinoya diagnostic criteria and 5 healthy controls who did not have TAO-related symptoms in their family histories.

METHODS

The Clariom D Affymetrix platform was used to conduct microarray analysis on total RNA extracted from whole blood. A total of 477 genes (FC ≤ 5 or >5) common to the fifteen patient and five control samples were selected using comparative microarray analysis; among them, 79 genes were upregulated and 398 genes were downregulated.

RESULTS

According to FC ≤ 10 or >10, in the same TAO patient and control group, 13 genes out of 28 were upregulated, whereas 15 genes were downregulated. The 11 key genes identified according to their mean log2FC values were PLP2, RPL27A, CCL4, FMNL1, EGR1, EIF4A1, RPL9, LAMP2, RNF149, EIF4G2, and DGKZ. The genes were ranked according to their relative expression as follows: FMNL1 > RNF149 > RPL27A > EIF4G2 > EIF4A1 > LAMP2 > EGR1 > PLP2 > DGKZ > RPL9 > CCL4. Using protein-protein interaction network analysis, RPL9, RPL27A, and RPL32 were found to be closely related to EIF4G2 and EIF4A1. The Reactome pathway found pathways linked to 28 genes. These pathways included the immune system, cellular responses to stress, cytokine signaling in the immune system, and signaling by ROBO receptors.

CONCLUSIONS

By figuring out the protein expression levels of the genes that have been found to explain how TAO disease works at the molecular level, it will be possible to figure out how well these chosen transcripts can diagnose and predict the disease.

Milestones in thromboangiitis obliterans. A position paper of the VAS-European Independent Foundation in Angiology/Vascular Medicine

BACKGROUND

Unfortunately, even today Thromboangiitis Obliterans has disease features that remain misunderstood or underappreciated. The epidemiology, etiology and pathophysiology of the disease are still unclear. Biomarkers and disease activity markers are lacking, thus clinical assessment is difficult. We are still struggling to establish unique diagnostic, staging and treatment criteria. This is an academic-collaborative effort to describe the pathophysiology, the clinical manifestations, the diagnostic approach, and the challenges of management of patients with TAO.

METHODS

A systematic search for relevant studies dating from 1900 to the end of 2020 was performed on the PubMed, SCOPUS, and Science Direct databases.

RESULTS

Given the intriguing nature of presentation of TAO, its management, to some extent is not only different in different regions of the world but also varies within the same region. Following this project, we discovered ambiguity, overlap and lack of clear-cut criteria for management of TAO.

CONCLUSIONS AND RELEVANCE

An international group of experts however came to one conclusion. They all agree that management of TAO is in need of a call for action for a renewed global look with multi-center studies, to update the geographical distribution of the disease and to establish a unique set of diagnostic criteria and a consensus-based guideline for best treatment based on current evidence.

Optimal hematocrit in an artificial microvascular network

BACKGROUND

Higher hematocrit increases the oxygen-carrying capacity of blood but also increases blood viscosity, thus decreasing blood flow through the microvasculature and reducing the oxygen delivery to tissues. Therefore, an optimal value of hematocrit that maximizes tissue oxygenation must exist.

STUDY DESIGN AND METHODS

We used viscometry and an artificial microvascular network device to determine the optimal hematocrit in vitro. Suspensions of fresh red blood cells (RBCs) in plasma, normal saline, or a protein-containing buffer and suspensions of stored red blood cells (at Week 6 of standard hypothermic storage) in plasma with hematocrits ranging from 10 to 80% were evaluated.

RESULTS

For viscometry, optimal hematocrits were 10, 25.2, 31.9, 37.1, and 37.5% for fresh RBCs in plasma at shear rates of 3.2 or less, 11.0, 27.7, 69.5, and 128.5 inverse seconds. For the artificial microvascular network, optimal hematocrits were 51.1, 55.6, 59.2, 60.9, 62.3, and 64.6% for fresh RBCs in plasma and 46.4, 48.1, 54.8, 61.4, 65.7, and 66.5% for stored RBCs in plasma at pressures of 2.5, 5, 10, 20, 40, and 60 cm H₂ O.

CONCLUSION

Although exact optimal hematocrit values may depend on specific microvascular architecture, our results suggest that the optimal hematocrit for oxygen delivery in the microvasculature depends on perfusion pressure. Therefore, anemia in chronic disorders may represent a beneficial physiological response to reduced perfusion pressure resulting from decreased heart function and/or vascular stenosis. Our results may help explain why a therapeutically increasing hematocrit in such conditions with RBC transfusion frequently leads to worse clinical outcomes.